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A General Simulation Method for Complex Deformation of Irregular-Shaped Origami Configurations

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Acta Mechanica Solida Sinica 2024年第1期37卷 90-98页

作者： Zhaochen Dong Yichao Zhu Xu Guo State Key laboratory of Structural Analysis for Industrial Equipment Department of Engineering MechanicsInternational Research Center for Computational MechanicsDalian University of TechnologyDalian 116023China

Most existing treatments for origami-folding simulations have focused on regular-shaped *** article aims to introduce a general strategy for simulating and analyzing the deformation process of irregular shapes by means of computational capabilities *** better simulate origami deformation with folding orders,the concept of plane follow-up is introduced to achieve automated computer simulation of complex folding patterns,thereby avoiding intersection and penetration between *** on the evaluation criteria such as the lowest storage energy with tightening and the fastest pace from tightening to unfolding,the optimal crease distribution patterns for four irregular(‘N’-,‘T’-,‘O’-,and‘P’-shaped)origami configurations are then presented under five *** the dimensions of the origami are fixed,it is discovered that simpler folding patterns lead to faster deformation of the origami *** the folding complexity is fixed,higher strain energy results in more rapid origami expansion.

关键词： Irregular-shaped origami Complex deformation Computer-aided origami design General simulation

Discontinuous phase diagram of amorphous carbons

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National Science Review 2024年第4期11卷 164-171页

作者： YinBo Zhu ZhouYu Fang ZhongTing Zhang HengAn Wu CAS Key laboratory of Mechanical Behavior and Design of Materials Department of Modern MechanicsUniversity of Science and Technology of China State Key laboratory of Nonlinear mechanics Institute of Mechanics Chinese Academy of Sciences

The short-range order and medium-range order of amorphous carbons demonstrated in experiments allow us to rethink whether there exist intrinsic properties hidden by atomic disordering. Here we presented six representative phases of amorphous carbons（0.1–3.4 g/cm3）, namely, disordered graphene network（DGN）, high-density amorphous carbon（HDAC）, amorphous diaphite（a-DG）, amorphous diamond（a-D）, paracrystalline diamond（p-D）, and nano-polycrystalline diamond（NPD）, respectively, classified by their topological features and microstructural characterizations that are comparable with experiments. To achieve a comprehensive physical landscape for amorphous carbons, a phase diagram was plotted in the sp3/sp2versus density plane, in which the counterintuitive discontinuity originates from the inherent difference in topological microstructures, further guiding us to discover a variety of phase transitions among different amorphous carbons. Intriguingly, the power law, log（sp3/sp2） ∝ ρn, hints at intrinsic topology and hidden order in amorphous carbons, providing an insightful perspective to reacquaint atomic disorder in non-crystalline carbons.

关键词： amorphous carbons disordered carbons phase diagram microstructural topology phase transition

Effect of boundary conditions on shakedown analysis of heterogeneous materials

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Applied Mathematics and mechanics(English Edition) 2024年第1期45卷 39-68页

作者： Xiuchen GONG Yinghao NIE Gengdong CHENG Kai LI State Key laboratory of Structural Analysis Optimization and CAE Software for Industrial EquipmentInternational Research Center for Computational MechanicsDepartment of Engineering MechanicsDalian University of TechnologyDalian 116023Liaoning ProvinceChina

The determination of the ultimate load-bearing capacity of structures made of elastoplastic heterogeneous materials under varying loads is of great importance for engineering analysis and design. Therefore, it is necessary to accurately predict the shakedown domains of these materials. The static shakedown theorem, also known as Melan's theorem, is a fundamental method used to predict the shakedown domains of structures and materials. Within this method, a key aspect lies in the construction and application of an appropriate self-equilibrium stress field(SSF). In the structural shakedown analysis, the SSF is typically constructed by governing equations that satisfy no external force(NEF) boundary conditions. However, we discover that directly applying these governing equations is not suitable for the shakedown analysis of heterogeneous materials. researchers must consider the requirements imposed by the Hill-Mandel condition for boundary conditions and the physical significance of representative volume elements(RVEs). This paper addresses this issue and demonstrates that the sizes of SSFs vary under different boundary conditions, such as uniform displacement boundary conditions(DBCs), uniform traction boundary conditions(TBCs), and periodic boundary conditions(PBCs). As a result, significant discrepancies arise in the predicted shakedown domain sizes of heterogeneous materials. Built on the demonstrated relationship between SSFs under different boundary conditions, this study explores the conservative relationships among different shakedown domains, and provides proof of the relationship between the elastic limit(EL) factors and the shakedown loading factors under the loading domain of two load vertices. By utilizing numerical examples, we highlight the conservatism present in certain results reported in the existing literature. Among the investigated boundary conditions, the obtained shakedown domain is the most conservative under ***, utilizing PBCs to

关键词： heterogeneous material self-equilibrium stress field(SSF) shakedown analysis effect of boundary conditions

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Analysis of thermal management and anti-mechanical abuse of multi-functional battery modules based on magneto-sensitive shear thickening fluid

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Applied Mathematics and mechanics(English Edition) 2024年第3期45卷 529-542页

作者： Yang XIONG Bo LU Yicheng SONG Junqian ZHANG Shanghai Key laboratory of mechanics in Energy Engineering Shanghai Frontier Science Center of MechanoinformaticsShanghai Institute of Applied Mathematics and MechanicsSchool of Mechanics and Engineering ScienceShanghai UniversityShanghai 200444China Zhejiang laboratory Hangzhou 311100China

Electric vehicles(EVs)have garnered significant attention as a vital driver of economic growth and environmental ***,ensuring the safety of high-energy batteries is now a top priority that cannot be overlooked during large-scale *** paper proposes an innovative active protection and cooling integrated battery module using smart materials,magneto-sensitive shear thickening fluid(MSTF),which is specifically designed to address safety threats posed by lithium-ion batteries(LIBs)exposed to harsh mechanical and environmental *** theoretical framework introduces a novel approach for harnessing the smoothed-particle hydrodynamics(SPH)methodology that incorporates the intricate interplay of non-Newtonian fluid behavior,capturing the fluid-structure coupling inherent to the *** approach is further advanced by adopting an enhanced Herschel-Bulkley(H-B)model to encapsulate the intricate rheology of the MSTF under the influence of the magnetorheological effect(MRE)and shear thickening(ST)*** simulation results show that in the case of cooling,the MSTF is an effective cooling medium for rapidly reducing the *** terms of mechanical abuse,the MSTF solidifies through actively applying the magnetic field during mechanical compression and impact within the battery module,resulting in 66%and 61.7%reductions in the maximum stress within the battery jellyroll,and 31.1%and 23%reductions in the reaction force,*** mechanism effectively lowers the risk of short-circuit *** groundbreaking concepts unveiled in this paper for active protection battery modules are anticipated to be a valuable technological breakthrough in the areas of EV safety and lightweight/integrated design.

关键词： magneto-sensitive shear thickening fluid(MSTF) battery module impact protection temperature control integrated design

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Observing strain glass transition in Ti_(33)Nb_(15)Zr_(25)Hf_(25)O_(2)high entropy alloy with Elinvar effect

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Journal of Materials Science & Technology 2024年第1期168卷 16-23页

作者： Kaichao Zhang Kai Wang Bin Wang Chao Lv Jiaxing Zheng Guanqi Li Yu Fu Wenlong Xiao Qingqing Cai Xutao Nie Yingfeng Shao Huilong Hou Xinqing Zhao School of Materials Science and Engineering Beihang UniversityBeijing 100191China China Aerodynamics research and Development Center Mianyang 621000China State Key laboratory of Nonlinear mechanics Chinese Academy of SciencesInstitute of MechanicsBeijing 100190China Tianmushan laboratory(Zhejiang Provincial laboratory for Aviation) Hangzhou 310000China

Exploring the phase transition of high entropy alloys(HEAs)with multiple major elements is of great importance for understanding the underlying physical *** martensitic phase tran-sition has been frequently reported in HEAs,however,nanoscale microstructural phase evolution has not been investigated to the same ***,we have prepared the Ti_(33)Nb_(15)Zr_(25)Hf_(25)O_(2)HEA and investi-gated the strain glass transition and its associated properties using dynamic mechanical analysis and mi-crostructure *** have found that the elastic modulus in Ti_(33)Nb_(15)Zr_(25)Hf_(25)O_(2)HEA deviates from Wachtman’s equation and observed the Elinvar effect in the form of temperature-independent mod-ulus in the temperature range from 150 K to 450 K and frequency-dependence modulus around 220 *** strain glass transition has been evidenced in Ti_(33)Nb_(15)Zr_(25)Hf_(25)O_(2)HEA by the formation and growth of nano-sized domains during in-situ transmission electron microscopy(TEM)cooling,and substantiated by the broken ergodicity during zero-field-cooling/*** strain glass transition is believed to account for the Elinvar effect,where the modulus hardening of nano-sized domains compensates dynam-ically with the modulus softening of the transformable matrix.

关键词： High entropy alloys Strain glass transition Elinvar effect Microstructural evolution Nanodomains

Dynamic analysis of a novel multilink-spring mechanism for vibration isolation and energy harvesting

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Chinese Physics B 2024年第5期33卷 366-379页

作者：谢佳衡杨涛唐介 research & Development Institute of Northwestern Polytechnical University in Shenzhen Shenzhen 518057China Department of Engineering mechanics Northwest Polytechnical UniversityXi'an 710072China Applied mechanics and Structure Safety Key laboratory of Sichuan Province School of Mechanics and AerospaceSouthwest Jiaotong UniversityChengdu 610031China

Due to technical limitations,existing vibration isolation and energy harvesting(VIEH)devices have poor performance at low *** paper proposes a new multilink-spring mechanism(MLSM)that can be used to solve this *** VIEH performance of the MLSM under harmonic excitation and Gaussian white noise was *** was found that the MLSM has good vibration isolation performance for low-frequency isolation and the frequency band can be widened by adjusting parameters to achieve a higher energy harvesting *** comparison with two special cases,the results show that the MLSM is basically the same as the other two oscillators in terms of vibration isolation but has better energy harvesting performance under multistable *** MLSM is expected to reduce the impact of vibration on high-precision sensitive equipment in some special sites such as subways and mines,and at the same time supply power to structural health monitoring devices.

关键词： multilink-spring mechanism nonlinear dynamics vibration isolation energy harvester

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Numerical Analysis of Permeability of Functionally Graded Scaffolds

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Fluid Dynamics and Materials Processing 2024年第7期20卷 1463-1479页

作者： Bratsun D. Elenskaya N. Siraev R. Tashkinov M. laboratory of mechanics of Biocompatible Materials and Devices Perm National Research Polytechnic University Perm 614990 Russian Federation

In this work, we numerically study the hydrodynamic permeability of new-generation artificial porous materials used as scaffolds for cell growth in a perfusion bioreactor. We consider two popular solid matrix designs based on triply periodic minimal surfaces, the Schwarz P (primitive) and D (diamond) surfaces, which enable the creation of materials with controlled porosity gradients. The latter property is crucial for regulating the shear stress field in the pores of the scaffold, which makes it possible to control the intensity of cell growth. The permeability of functionally graded materials is studied within the framework of both a microscopic approach based on the Navier-Stokes equation and an averaged description of the liquid filtration through a porous medium based on the equations of the Darcy or Forchheimer models. We calculate the permeability coefficients for both types of solid matrices formed by Schwarz surfaces, study their properties concerning forward and reverse fluid flows, and determine the ranges of Reynolds number for which the description within the Darcy or Forchheimer model is applicable. Finally, we obtain a shear stress field that varies along the sample, demonstrating the ability to tune spatially the rate of tissue growth. © This work is licensed under a Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

关键词： filtration models functionally graded materials Porous media scaffolds

A vibration isolator with a controllable quasi-zero stiffness region based on nonlinear force design

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Applied Mathematics and mechanics(English Edition) 2024年第8期45卷 1279-1294页

作者： Xinyu LIAN Bing LIU Huaxia DENG Xinglong GONG CAS Key laboratory of Mechanical Behavior and Design of Materials Department of Modern Mechanics University of Science and Technology of China State Key laboratory of Nonlinear mechanics Institute of MechanicsChinese Academy of Sciences State Key laboratory of Fire Science University of Science and Technology of China

To achieve stability optimization in low-frequency vibration control for precision instruments, this paper presents a quasi-zero stiffness(QZS) vibration isolator with adjustable nonlinear stiffness. Additionally, the stress-magnetism coupling model is established through meticulous theoretical derivation. The controllable QZS interval is constructed via parameter design and magnetic control, effectively segregating the high static stiffness bearing section from the QZS vibration isolation section. Furthermore, a displacement control scheme utilizing a magnetic force is proposed to regulate entry into the QZS working range for the vibration isolation platform. experimental results demonstrate that the operation within this QZS region reduces the peak-to-peak acceleration signal by approximately 66.7% compared with the operation outside this region, thereby significantly improving the low frequency performance of the QZS vibration isolator.

关键词： 70K20 low frequency nonlinear O328 quasi-zero stiffness (QZS) vibration isolator

Review of dynamics and active control of large-scale space membrane antenna

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Astrodynamics 2024年第1期8卷 1-26页

作者： Xiang Liu Guoping Cai Department of Engineering mechanics MOE Key Laboratory of HydrodynamicsChongqing Research InstituteShanghai Jiao Tong UniversityShanghai200240China

Large-scale space membrane antennas have significant potential in satellite communication,space-based early warning,and Earth *** of their large size and high flexibility,the dynamic analysis and control of membrane antenna are *** maintain the working performance of the antenna,the pointing and surface accuracies must be strictly ***,the accurate dynamic modeling and effective active control of large-scale space membrane antennas have great theoretical significance and practical value,and have attracted considerable interest in recent *** paper reviews the dynamics and active control of large-scale space membrane ***,the development and status of large-scale space membrane antennas are ***,the key problems in the dynamics and active control of large membrane antennas,including the dynamics of wrinkled membranes,large-amplitude nonlinear vibration,nonlinear model reduction,rigid-flexible-thermal coupling dynamic modeling,on-orbit modal parameter identification,active vibration control,and wave-based vibration control,are discussed in ***,the research outlook and future trends are presented.

关键词： large-scale space membrane antenna dynamicmodeling active control